1) Mywifiext.net is a website that allows you to configure a Netgear wireless extender, but can only be accessed when connected to the extender's wireless network. 2) The document provides troubleshooting tips for issues like being unable to access mywifiext.net, not seeing the Netgear Genie software, or the setup repeatedly asking for the passphrase. Suggested solutions include checking the extender's lights and wiring, reassigning device IP addresses, and moving the extender closer to the router. 3) Instructions are given for resetting the extender by holding the reset button for 7 seconds, which will restore the default username and password.